Resilient tomatoes – Grafting techniques offer new opportunities for Cambodian farmers

Similar to other countries in South-East Asia, Cambodia experiences distinct dry- and wet seasons each year. While the dry period makes it difficult for farmers to maintain their crops due to lack of water, the rains in the months between May and October come with different challenges: Waterlogging and bacterial wilt cause significant losses, making especially small holder farmers, who depend on their vegetables for food and income, more vulnerable.

Farmers in the CHAIN project's four target provinces experience the effects of excessive rain fall on their crops each year. Especially plants of the Solanaceae family, including tomato, eggplant, and chili, are affected. Since these vegetables are always in demand as an essential part of the Cambodian diet, and are among the most commonly grown vegetables in the country, a high number of farmers suffer the consequences if they cannot prevent their crops from wilting.

In response, the CHAIN project and the World Vegetable Centre are currently introducing grafting to make crops more resistant against water logging and control bacterial wilt, fusarium wilt, and root-knot nematodes. The first trials, which started this season, use the rootstock of three eggplant varieties and five different tomato varieties as scions, which is the upper part of the plant. PDAFF and a number of NGOs, as well as private sector companies, are involved in introducing this technique to the provinces. A first step was taken on 22nd August this year, when the CHAIN project partners and five farmers received a three-day training in Stung Treng province with the technical support of international experts from the World Vegetable Centre. The training sessions covered both theory and practice of the grafting technique. Three of the farmers had previously planted the eggplant varieties with resistant roots on a total of 2,031 m2, for which seeds were provided by Agriance, EAC, and EWSF. These eggplants were used for seed multiplication in preparation for coming seasons and to share with farmers in other provinces. The companies also provided seeds for five high-yielding tomato varieties which, combined with the rootstock of the eggplant, will allow farmers to produce tomatoes even during the wet season, achieving a higher price on the market.

Within the next season, CHAIN expects to expand the technique to all CHAIN target provinces. However, there are always challenges associated with introducing new techniques: CHAIN, together with partners and farmers, is still learning about adapting the technique to different geographies of the target provinces. Therefore, CHAIN’s technical staff and the World Vegetable Centre will coach partners to prepare them for a rollout of the intervention. The seed multiplication and collection is still ongoing, and it is expected that enough rootstock seeds will become available to continue grafting with the resilient eggplant varieties.

In the meantime, two of the attending farmers already applied what they learned in practice and used 1.890m2 of their land to plant 2,520 grafted plants. Their experience will be used to assess the success of the grafting this season. The first harvest is expected in November, while three other farmers will start grafting on their own by October 2017 and harvest a second round of resilient tomatoes in December this year.